Setting a Time Machine size limit

To create a Time Machine size limit in Leopard, simply issue the following command in the terminal:

Size is measured in megabytes- my example is 100GB.

A year later, this does not appear to work (even after using the integer option).  Here is the code to reverse this change:

defaults delete /Library/Preferences/com.apple.TimeMachine MaxSize

The accepted way to limit the size now is to create a sparse disk image.